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Day: 20130109

Jan. 8, 2013 — The question ‘How do songbirds sing?’ is addressed in a study published in BioMed Central’s open access journal BMC Biology. High-field magnetic resonance imaging and micro-computed tomography have been used to construct stunning high resolution, 3D, images, as well as a data set “morphome” of the zebra finch (Taeniopygia guttata) vocal organ, the syrinx.

Like humans, songbirds learn their vocalizations by imitation. Since their songs are used for finding a mate and retaining territories, birdsong is very important for reproductive success.

The syrinx, located at the point where the trachea splits in two to send air to the lungs, is unique to birds and performs the same function as vocal cords in humans. Birds can have such a complete control over the syrinx, with sub-millisecond precision, that in some cases they are even able to mimic human speech.

Despite great inroads in uncovering the neural control of birdsong, the anatomy of the complex physical structures that generate sound have been less well understood.

The multinational team has generated interactive 3D PDF models of the syringeal skeleton, soft tissues, cartilaginous pads, and muscles affecting sound production. These models show in detail the delicate balance between strength, and lightness of bones and cartilage required to support and alter the vibrating membranes of the syrinx at superfast speeds.

Dr Coen Elemans, from the University of Southern Denmark, who led this study, explained, “This study provides the basis to analyze the micromechanics, and exact neural and muscular control of the syrinx. For example, we describe a cartilaginous structure which may allow the zebra finch to precisely control its songs by uncoupling sound frequency and volume.” In addition, the researchers found a previously unrecognized Y-shaped structure on the sternum which corresponds to the shape of the syrinx and could help stabilize sound production.

Jan. 7, 2013 — Red wine could give athletes and players a boost in the sports arena by increasing the amount of performance-enhancing hormone testosterone in their bodies, according to researchers from London’s Kingston University.

However not only could the beverage help them to trophy success, it could also allow them to beat anti-doping tests. A team led by Professor Declan Naughton, from the University’s School of Life Sciences, found that red wine might reduce the amount of testosterone excreted by the body, which could distort the findings of drug tests taken from urine samples.

Testosterone is a naturally-occurring steroid hormone present in both men and women. It can increase muscle mass, boost stamina and speed up recovery. Sportspeople, however, are prohibited from taking it, or a synthetic version of it, to try to gain a competitive edge.

Although red wine is not a banned substance away from the sports field, Professor Naughton’s team has referred its findings to the World Anti-Doping Agency because of the newly-discovered side effect of potential change to the amount of testosterone in the body.

“Previous research has shown the effect over-the-counter anti-inflammatory drugs can have on enzymes,” Professor Naughton explained. “Since many of these drugs are derived from plants, we decided to look at the effect particular foods and beverages can have on enzymes involved in testosterone excretion. We chose green tea and then red wine because both have a huge variety of natural molecules and we wanted to see if they affected the amount of testosterone excreted in urine.”

The team found that a compound in red wine, known as quercetin, partially blocked the action of an enzyme called UGT2B17, which looks for testosterone and then sends a message to the kidneys to excrete it.

Professor Naughton stressed that the research had so far been conducted in test tube experiments and had yet to be trialled on humans. “A full clinical study would be needed to determine the effects on people but, if the same results were found, it would confirm that compounds in red wine can reduce the amount of testosterone in urine and give a boost to testosterone levels,” he explained.

The effect of red wine on an individual would vary because of factors such as weight, fitness, health and diet, making it hard to estimate how much was needed to improve performance, Professor Naughton said.

Teetotallers are not exempt from the effects. In fact, the alcohol content of red wine has very little impact because non-alcoholic molecules are responsible for inhibiting testosterone excretion.

The team also found the results were the same for red wine extract in supplement form. The active compounds such as quercetin are found in many foodstuffs as well as supplements.

The findings have been published in leading international journal Nutrition. The research follows an earlier study from Professor Naughton’s team which showed that green and white tea could also inhibit testosterone excretion.

an. 7, 2013 — Social practices and cultural beliefs of modern life are preventing healthy brain and emotional development in children, according to an interdisciplinary body of research presented recently at a symposium at the University of Notre Dame.

“Life outcomes for American youth are worsening, especially in comparison to 50 years ago,” says Darcia Narvaez, Notre Dame professor of psychology who specializes in moral development in children and how early life experiences can influence brain development.

“Ill-advised practices and beliefs have become commonplace in our culture, such as the use of infant formula, the isolation of infants in their own rooms or the belief that responding too quickly to a fussing baby will ‘spoil’ it,” Narvaez says.

This new research links certain early, nurturing parenting practices — the kind common in foraging hunter-gatherer societies — to specific, healthy emotional outcomes in adulthood, and has many experts rethinking some of our modern, cultural child-rearing “norms.”

“Breast-feeding infants, responsiveness to crying, almost constant touch and having multiple adult caregivers are some of the nurturing ancestral parenting practices that are shown to positively impact the developing brain, which not only shapes personality, but also helps physical health and moral development,” says Narvaez.

Studies show that responding to a baby’s needs (not letting a baby “cry it out”) has been shown to influence the development of conscience; positive touch affects stress reactivity, impulse control and empathy; free play in nature influences social capacities and aggression; and a set of supportive caregivers (beyond the mother alone) predicts IQ and ego resilience as well as empathy.

The United States has been on a downward trajectory on all of these care characteristics, according to Narvaez. Instead of being held, infants spend much more time in carriers, car seats and strollers than they did in the past. Only about 15 percent of mothers are breast-feeding at all by 12 months, extended families are broken up and free play allowed by parents has decreased dramatically since 1970.

Whether the corollary to these modern practices or the result of other forces, an epidemic of anxiety and depression among all age groups, including young children; rising rates of aggressive behavior and delinquency in young children; and decreasing empathy, the backbone of compassionate, moral behavior, among college students, are shown in research.

According to Narvaez, however, other relatives and teachers also can have a beneficial impact when a child feels safe in their presence. Also, early deficits can be made up later, she says.

“The right brain, which governs much of our self-regulation, creativity and empathy, can grow throughout life. The right brain grows though full-body experience like rough-and-tumble play, dancing or freelance artistic creation. So at any point, a parent can take up a creative activity with a child and they can grow together.”

Testing animals’ ability to solve new problems has been historically conducted on animals in captivity. Only recently has a shift been made to run these tests on animals in their natural habitat. In a study appearing in Animal Behaviour, however, researchers at Michigan State University found vast differences in the problem solving skills between captive and wild spotted hyenas.

Applying lessons learned from captive animals is potentially problematic because they may not accurately portray how wild animals respond to novel challenges, said Sarah Benson-Amram, former MSU zoology graduate student and the study’s lead author.

“We have to be careful when interpreting results from captive animals, as there may be extreme differences between how animals behave in captivity and in the wild,” said Benson-Amram, who is now a research fellow at the University of St. Andrews (Scotland). “An animal that is successful at solving problems in the comfort of its cage may be unwilling to engage in similar problem-solving behavior in the wild.”

Benson-Amram presented wild and captive spotted hyenas with the same novel problem — a steel puzzle box containing meat. Captive hyenas were significantly better at opening their boxed meals than their wild counterparts. The encaged mammals also were less afraid of the humanmade puzzle, and they also were more creative, trying a variety of solutions.

“It doesn’t appear that these differences result from captive hyenas having more time or energy,” Benson-Amram said. “We conclude they were more successful because they were more willing to tackle the problem and were more exploratory.”

Benson-Amram teamed up with Kay Holekamp, MSU zoologist and co-principal investigator at the BEACON Center for the Study of Evolution in Action, and Mary Weldele with the University of California Berkeley. The research was funded in part by the National Science Foundation.

Jan. 7, 2013 — Short interruptions — such as the few seconds it takes to silence that buzzing smartphone — have a surprisingly large effect on one’s ability to accurately complete a task, according to new research led by Michigan State University.

The study, in which 300 people performed a sequence-based procedure on a computer, found that interruptions of about three seconds doubled the error rate.

Brief interruptions are ubiquitous in today’s society, from text messages to a work colleague poking his head in the door and interrupting an important conversation. But the ensuing errors can be disastrous for professionals such as airplane mechanics and emergency room doctors, said Erik Altmann, lead researcher on the study.

“What this means is that our health and safety is, on some level, contingent on whether the people looking after it have been interrupted,” said Altmann, MSU associate professor of psychology.

The study, funded by the U.S. Navy’s Office of Naval Research, is one of the first to examine brief interruptions of relatively difficult tasks. The findings appear in theJournal of Experimental Psychology: General.

Study participants were asked to perform a series of tasks in order, such as identifying with a keystroke whether a letter was closer to the start or the end of the alphabet. Even without interruptions a small number of errors in sequence were made.

Sometimes participants were interrupted and told to type two letters — which took 2.8 seconds — before returning to the task. When this happened, they were twice as likely to mess up the sequence.

Altmann said he was surprised that such short interruptions had a large effect. The interruptions lasted no longer than each step of the main task, he noted, so the time factor likely wasn’t the cause of the errors.

“So why did the error rate go up?” Altmann said. “The answer is that the participants had to shift their attention from one task to another. Even momentary interruptions can seem jarring when they occur during a process that takes considerable thought.”

One potential solution, particularly when errors would be costly, is to design an environment that protects against interruptions. “So before you enter this critical phase: All cell phones off at the very least,” Altmann said.

His co-authors are Gregory Trafton of the Naval Research Laboratory and Zach Hambrick of MSU.

an. 4, 2013 — Physical inactivity is a major public health problem that has both social and neurobiological causes. According to the results of an Ipsos survey published on December 31, the French have put “taking up a sport” at the top of their list of good resolutions for 2013. However, Francis Chaouloff, research director at Inserm’s NeuroCentre Magendie (Inserm Joint Research Unit 862, Université Bordeaux Ségalen), Sarah Dubreucq, a PhD student and François Georges, a CNRS research leader at the Interdisciplinary Institute for Neuroscience (CNRS/Université Bordeaux Ségalen) have just discovered the key role played by a protein, the CB1 cannabinoid receptor, during physical exercise. In their mouse studies, the researchers demonstrated that the location of this receptor in a part of the brain associated with motivation and reward systems controls the time for which an individual will carry out voluntary physical exercise. These results were published in the journal Biological Psychiatry.

The collective appraisal conducted by Inserm in 2008 highlighted the many preventive health benefits of regular physical activity. Such activity is limited, however, by our lifestyle in today’s industrial society. While varying degrees of physical inactivity may be partly explained by social causes, they are also rooted in biology.

“The inability to experience pleasure during physical activity, which is often quoted as one explanation why people partially or completely drop out of physical exercise programmes, is a clear sign that the biology of the nervous system is involved,” explains Francis Chaouloff.

But how exactly? The neurobiological mechanisms underlying physical inactivity had yet to be identified.

Francis Chaouloff (Giovanni Marsicano’s team at the NeuroCentre Magendie; Inserm joint research unit, Université Bordeaux Ségalen) and his team have now begun to decipher these mechanisms. Their work clearly identifies the endogenous cannabinoid (or endocannabinoid) system as playing a decisive role, in particular one of its brain receptors. This is by no means the first time that data has pointed to interactions between the endocannabinoid system, which is the target of delta9-tetrahydrocannabinol (the active ingredient of cannabis), and physical exercise. It was discovered ten years ago that physical exercise activated the endocannabinoid system in trained sportsmen, but its exact role remained a mystery for many years. Three years ago, the same research team in Bordeaux observed that when given the opportunity to use a running wheel, mutant mice lacking the CB1 cannabinoid receptor, which is the principal receptor of the endocannabinoid system in the brain, ran for a shorter time and over shorter distances than healthy mice. The research published in Biological Psychiatry this month seeks to understand how, where and why the lack of CB1 receptor reduces voluntary exercise performance (by 20 to 30%) in mice allowed access to a running wheel three hours per day.

The researchers used various lines of mutant mice for the CB1 receptor, together with pharmacological tools. They began by demonstrating that the CB1 receptor controlling running performance is located at the GABAergic nerve endings. They went on to show that the receptor is located in the ventral tegmental area of the brain (see diagram below), which is an area involved in motivational processes relating to reward, whether the reward is natural (food, sex) or associated with the consumption of psychoactive substances.

Based on the results of this study and earlier work, the Bordeaux team suggests the following neurobiological explanation: at the beginning and for the duration of physical exercise, the CB1 receptor is constantly simulated by the endocannabinoids, lipid molecules that naturally activate this receptor in response to pleasant stimuli (rewards) and unpleasant stimuli (stress). Endocannabinoid stimulation of the CB1 receptor during physical exercise inhibits the release of GABA, an inhibitory neurotransmitter that controls the activity of the dopamine neurons associated with the motivation and reward processes. This stimulation of the CB1 receptor “inhibits inhibition,” in other words, it activates the dopaminergic neurons in the ventral tegmental area. The CB1 receptor must therefore be stimulated before the exercise can go on for longer and the body must receive the necessary motivation.

Conversely, without these CB1 receptors, the “GABAergic brake” continues to act on the dopaminergic neurons in the ventral tegmental area, leading to the reduced performance levels observed above.

It is already known that CB1 receptors play a regulatory role in the motivation to consume rewards, whether natural or not. What is original about this research is that it shows that physical exercise can be added to the array of natural rewards regulated by the endocannabinoid system. “If confirmed, this motivational hypothesis would imply that the role played by the CB1 receptor has more to do with ‘staying power’ in the exercise than with actual physical performance levels” explain the researchers.

This work reveals that the endocannabinoid system plays a major role in physical exercise performance through its impact on motivational processes. It thus opens up new avenues of research into the mediators of pleasure — and even addiction — associated with regular physical exercise. “After endorphins, we now need to consider endocannabinoids as another potential mediator of the positive effects that physical exercise has on our mood,” the researchers conclude.

Jan. 4, 2013 — Spanish researchers have traced the bacterial microbiota map in breast milk, which is often the main source of nourishment for newborns. The study has revealed a larger microbial diversity than originally thought: more than 700 species.

Lactobacillus. (Credit: Janice Carr)

The breast milk received from the mother is one of the factors determining how the bacterial flora will develop in the newborn baby. However, the composition and the biological role of these bacteria in infants remain unknown.

A group of Spanish scientists have now used a technique based on massive DNA sequencing to identify the set of bacteria contained within breast milk called microbiome. Thanks to their study, pre- and postnatal variables influencing the micriobial richness of milk can now be determined.

Colostrum is the first secretion of the mammary glands after giving birth. In some of the samples taken of this liquid, more than 700 species of these microorganisms were found, which is more than originally expected by experts. The results have been published in theAmerican Journal of Clinical Nutrition.

“This is one of the first studies to document such diversity using the pyrosequencing technique (a large scale DNA sequencing determination technique) on colostrum samples on the one hand, and breast milk on the other, the latter being collected after one and six months of breastfeeding,” explain the coauthors, María Carmen Collado, researcher at the Institute of Agrochemistry and Food Technology (IATA-CSIC) and Alex Mira, researcher at the Higher Public Health Research Centre (CSISP-GVA).

The most common bacterial genera in the colostrum samples were Weissella, Leuconostoc, Staphylococcus, Streptococcus and Lactococcus. In the fluid developed between the first and sixth month of breastfeeding, bacteria typical of the oral cavity were observed, such as Veillonella, Leptotrichia andPrevotella.

“We are not yet able to determine if these bacteria colonise the mouth of the baby or whether oral bacteria of the breast-fed baby enter the breast milk and thus change its composition,” outline the authors.

The heavier the mother, the fewer the bacteria

The study also reveals that the milk of overweight mothers or those who put on more weight than recommended during pregnancy contains a lesser diversity of species.

The type of labour also affects the microbiome within the breast milk: that of mothers who underwent a planned caesarean is different and not as rich in microorganisms as that of mothers who had a vaginal birth. However, when the caesarean is unplanned (intrapartum), milk composition is very similar to that of mothers who have a vaginal birth.

These results suggest that the hormonal state of the mother at the time of labour also plays a role: “The lack of signals of physiological stress, as well as hormonal signals specific to labour, could influence the microbial composition and diversity of breast milk,” state the authors.

Help for the food industry

Given that the bacteria present in breast milk constitute one of initial instances of contact with microorganisms that colonise the infant’s digestive system, the researchers are now working to determine if their role is metabolic (it helps the breast-fed baby to digest the milk) or immune (it helps to distinguish beneficial or foreign organisms).

For the authors, the results have opened up new doors for the design of child nutrition strategies that improve health. “If the breast milk bacteria discovered in this study were important for the development of the immune system, its addition to infant formula could decrease the risk of allergies, asthma and autoimmune diseases,” conclude the authors.

Jan. 3, 2013 — So, is it a girl or a boy? This is the first question parents ask at the birth of an infant. Though the answer is obvious, the mechanism of sex determination is much less so. Researchers at the University of Geneva (UNIGE) attempt to shed light on this complex process by identifying the crucial role played by insulin and IGF1 and IGF2 growth factors, a family of hormones known for its role in metabolism and growth. In the absence of these factors at the time of sex determination, embryos do not differentiate into either male or female and have no adrenal glands. The results of this study, published in the journal PLOS Genetics, allow us to better understand sexual development and will eventually improve diagnosis and genetic counseling practices for individuals with disorders of sex development.

In mammals, sexual development is a long process beginning at conception when the sperm’s transmission of an X or Y sex chromosome will determine the genetic sex of the embryo. The following developmental stages will translate this genetic sex into gonadal sex, that is, either ovaries or testes, which will secrete hormones that will masculinize or feminize the fetus.

The intention of the study conducted by Serge Nef, Professor at the Department of Genetic Medicine and Development at UNIGE, is to better understand the first stages of sexual development.

Growth, metabolism and reproduction

The researchers were interested in the role of a class of hormones, insulin-like growth factors (IGFs), and their receptors in cells. These factors, known to be involved in the regulation of metabolism and growth, also have a key role in the regulation of reproductive capacities of the individual, whether male or female. Reproductive function is, in fact, closely linked to metabolism and growth. This is actually quite logical: the growth of an individual cannot progress normally without adequate energy intake and there is no point in reproducing if this caloric intake is insufficient. This may explain why some women with anorexia have anovulatory cycles and may suffer from infertility. Conversely, people with morbid obesity also have significant disturbances in their fertility. Though it is now recognized that the interactions between metabolism, growth and reproductive capacity are regulated by common factors such as insulin and IGFs, Professor Nef’s study shows that these interactions are even more important than previously believed because the insulin and IGF receptors are also essential for primary sex determination in mammals.

To analyze the impact of these hormones on sex determination, Professor Nef’s group used genetically modified mice. The scientists genetically inactivated the receptors for insulin and IGFs in mouse embryos. They then discovered that in the absence of these factors, at the time of sex determination, the gonads of mutant embryos were unable to develop into testes or ovaries. As such, the embryo and its gonads remained stuck in a fully undifferentiated state for several days demonstrating the essential role of these hormones and growth factors in sexual differentiation.

In humans, cases of disorders of sex development are relatively common with about 1 newborn in every 3000 births being affected. Unfortunately, in the majority of cases, the genetic causes of such alterations remain unexplained. “This study provides a better understanding of the basic mechanisms of sexual development and is a step forward towards a better understanding of the causes of sexual ambiguities, which often remain unknown,” states Professor Nef. “The research we are conducting will provide the opportunity to refine and improve clinical diagnosis of individuals with disorders of sex development.”

Jan. 3, 2013 — Using brain scans of children and adults watching Sesame Street, cognitive scientists are learning how children’s brains change as they develop intellectual abilities like reading and math.

The fMRI scan on the left represents correlations in neural activity between children and adults, in the middle between children and other children, and on the right between adults and other adults. Such neural maps, says University of Rochester cognitive scientist Jessica Cantlon, reveal how the brain’s neural structure develops along predictable pathways as we mature. (Credit: Jessica Cantlon, University of Rochester)

The novel use of brain imaging during everyday activities like watching TV, say the scientists, opens the door to studying other thought processes in naturalistic settings and may one day help to diagnose and treat learning disabilities.

Scientists are just beginning to use brain imaging to understand how humans process thought during real-life experiences. For example, researchers have compared scans of adults watching an entertaining movie to see if neural responses are similar across different individuals. “But this is the first study to use the method as a tool for understanding development,” says lead author Jessica Cantlon, an assistant professor in brain and cognitive sciences at the University of Rochester.

Eventually, that understanding may help pinpoint the cause when a child experiences difficulties mastering school work. “Psychologists have behavioral tests for trying to get the bottom of learning impairments, but these new imaging studies provide a totally independent source of information about children’s learning based on what’s happening in the brain,” says Cantlon.

The neuroimaging findings are detailed in a new study published Jan. 3 by the Public Library of Science’s open-access journal PLoS Biology, by Cantlon and her former research assistant Rosa Li, now a graduate student at Duke University.

For the investigation, 27 children between the ages of 4 and 11, and 20 adults watched the same 20-minute Sesame Street video. Like the regular program, the recording featured a variety of short clips focused on numbers, words, shapes, and other subjects. The children then took standardized IQ tests for math and verbal ability.

To capture the neural response to the show, the researchers turned to functional magnetic resonance imaging (fMRI) scans. Unlike X-rays, CAT scans, and other types of brain imaging, fMRI involves no risks, injections, surgery, or exposure to radiation. Using magnetic fields, the scans virtually segment the brain into a three-dimensional grid of about 40,000 pixels, known as voxels, and measure the neural signal intensity in each of those tiny sectors. The study produced 609 scans of each participant, one every two seconds, as they watched Big Bird, the Count, Elmo and other stars of the educational series. Using statistical algorithms, the researchers then created “neural maps” of the thought processes for the children and the adults and compared the groups.

The result? Children whose neural maps more closely resembled the neural maps of adults scored higher on standardized math and verbal tests. In other words, the brain’s neural structure, like other parts of the body, develops along predictable pathways as we mature.

The study also confirmed where in the brain these developing abilities are located. For verbal tasks, adult-like neural patterns in the Broca area, which is involved in speech and language, predicted higher verbal test scores in children. For math, better scores were linked to more mature patterns in the intraparietal sulcus (IPS), a region of the brain known to be involved in the processing of numbers.

Using normal activities, like TV watching, may provide a more accurate indicator of children’s learning and brain development in the real world than the short and simple tasks typical of fMRI studies, the authors argue. Like the Sesame Street video, learning environments in schools are rich in complexity along with the academic lessons, write the authors.

To test that assumption, Cantlon and Li had the children perform traditional fMRI tasks by matching simple pictures of faces, numbers, words, or shapes. During these more limited activities with simple images, the neural responses of the children did not predict their test scores, unlike the more naturalistic task of watching Sesame Street.

Although the study does not advocate TV watching, it does show that “neural patterns during an everyday activity like watching television are related to a person’s intellectual maturity,” says Cantlon. “It’s not the case that if you put a child in front of an educational TV program that nothing is happening-that the brain just sort of zones out. Instead, what we see is that the patterns of neural activity that children are showing are meaningful and related to their intellectual abilities.”

Conducted at the Rochester Center for Brain Imaging, the study was supported by a National Institutes of Health grant (R01 HD064636) and by a James S. McDonnell Foundation grant to Cantlon.

This derivative of a dopamine-receptor gene — called the DRD4 7R allele — appears in significantly higher rates in people more than 90 years old and is linked to lifespan increases in mouse studies.

Robert Moyzis, professor of biological chemistry at UC Irvine, and Dr. Nora Volkow, a psychiatrist who conducts research at the Brookhaven National Laboratory and also directs the National Institute on Drug Abuse, led a research effort that included data from the UC Irvine-led 90+ Study in Laguna Woods, Calif. Results appear online in The Journal of Neuroscience.

The variant gene is part of the dopamine system, which facilitates the transmission of signals among neurons and plays a major role in the brain network responsible for attention and reward-driven learning. The DRD4 7R allele blunts dopamine signaling, which enhances individuals’ reactivity to their environment.

People who carry this variant gene, Moyzis said, seem to be more motivated to pursue social, intellectual and physical activities. The variant is also linked to attention-deficit/hyperactivity disorder and addictive and risky behaviors.

“While the genetic variant may not directly influence longevity,” Moyzis said, “it is associated with personality traits that have been shown to be important for living a longer, healthier life. It’s been well documented that the more you’re involved with social and physical activities, the more likely you’ll live longer. It could be as simple as that.”

Numerous studies — including a number from the 90+ Study — have confirmed that being active is important for successful aging, and it may deter the advancement of neurodegenerative diseases, such as Alzheimer’s.

Prior molecular evolutionary research led by Moyzis and Chuansheng Chen, UC Irvine professor of psychology & social behavior, indicated that this “longevity allele” was selected for during the nomadic out-of-Africa human exodus more than 30,000 years ago.

In the new study, the UC Irvine team analyzed genetic samples from 310 participants in the 90+ Study. This “oldest-old” population had a 66 percent increase in individuals carrying the variant relative to a control group of 2,902 people between the ages of 7 and 45. The presence of the variant also was strongly correlated with higher levels of physical activity.

Next, Volkow, neuroscientist Panayotis Thanos and their colleagues at the Brookhaven National Laboratory found that mice without the variant had a 7 percent to 9.7 percent decrease in lifespan compared with those possessing the gene, even when raised in an enriched environment.

While it’s evident that the variant can contribute to longevity, Moyzis said further studies must take place to identify any immediate clinical benefits from the research. “However, it is clear that individuals with this gene variant are already more likely to be responding to the well-known medical adage to get more physical activity,” he added.

First author Deborah Grady, Maria Corrada, Valentina Ciobanu, Alexandra Moyzis, Chuansheng Chen and Dr. Claudia Kawas of UC Irvine; Diana Shustarovich and Gene-Jack Wang of Brookhaven; David Grandy of Oregon Health & Science University; Marcelo Rubinstein of Argentina’s National Scientific & Technical Research Council; and Qi Dong of Beijing Normal University also contributed to the study, which was supported by the U.S. Department of Energy, the National Institute on Aging, and the National Institute on Alcohol Abuse & Alcoholism intramural program.